1 | !> @file lpm_advec.f90 |
---|
2 | !------------------------------------------------------------------------------! |
---|
3 | ! This file is part of the PALM model system. |
---|
4 | ! |
---|
5 | ! PALM is free software: you can redistribute it and/or modify it under the |
---|
6 | ! terms of the GNU General Public License as published by the Free Software |
---|
7 | ! Foundation, either version 3 of the License, or (at your option) any later |
---|
8 | ! version. |
---|
9 | ! |
---|
10 | ! PALM is distributed in the hope that it will be useful, but WITHOUT ANY |
---|
11 | ! WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR |
---|
12 | ! A PARTICULAR PURPOSE. See the GNU General Public License for more details. |
---|
13 | ! |
---|
14 | ! You should have received a copy of the GNU General Public License along with |
---|
15 | ! PALM. If not, see <http://www.gnu.org/licenses/>. |
---|
16 | ! |
---|
17 | ! Copyright 1997-2019 Leibniz Universitaet Hannover |
---|
18 | !------------------------------------------------------------------------------! |
---|
19 | ! |
---|
20 | ! Current revisions: |
---|
21 | ! ------------------ |
---|
22 | ! |
---|
23 | ! |
---|
24 | ! Former revisions: |
---|
25 | ! ----------------- |
---|
26 | ! $Id: lpm_advec.f90 3655 2019-01-07 16:51:22Z suehring $ |
---|
27 | ! variables documented |
---|
28 | ! |
---|
29 | ! 3274 2018-09-24 15:42:55Z knoop |
---|
30 | ! Modularization of all bulk cloud physics code components |
---|
31 | ! |
---|
32 | ! 3241 2018-09-12 15:02:00Z raasch |
---|
33 | ! unused variables removed |
---|
34 | ! |
---|
35 | ! 3207 2018-08-27 12:55:33Z schwenkel |
---|
36 | ! Minor bugfix for sgs-velocities in case of cloud droplets |
---|
37 | ! |
---|
38 | ! 3189 2018-08-06 13:18:55Z raasch |
---|
39 | ! Bugfix: Index of the array dzw has to be k+1 during the interpolation. |
---|
40 | ! Otherwise k=0 causes an abortion because dzw is allocated from 1 to nzt+1 |
---|
41 | ! |
---|
42 | ! 3065 2018-06-12 07:03:02Z Giersch |
---|
43 | ! dz values were replaced by dzw or dz(1) to allow for right vertical stretching |
---|
44 | ! |
---|
45 | ! 2969 2018-04-13 11:55:09Z thiele |
---|
46 | ! Bugfix in Interpolation indices. |
---|
47 | ! |
---|
48 | ! 2886 2018-03-14 11:51:53Z thiele |
---|
49 | ! Bugfix in passive particle SGS Model: |
---|
50 | ! Sometimes the added SGS velocities would lead to a violation of the CFL |
---|
51 | ! criterion for single particles. For this a check was added after the |
---|
52 | ! calculation of SGS velocities. |
---|
53 | ! |
---|
54 | ! 2718 2018-01-02 08:49:38Z maronga |
---|
55 | ! Corrected "Former revisions" section |
---|
56 | ! |
---|
57 | ! 2701 2017-12-15 15:40:50Z suehring |
---|
58 | ! Changes from last commit documented |
---|
59 | ! |
---|
60 | ! 2698 2017-12-14 18:46:24Z suehring |
---|
61 | ! Particle interpolations at walls in case of SGS velocities revised and not |
---|
62 | ! required parts are removed. (responsible Philipp Thiele) |
---|
63 | ! Bugfix in get_topography_top_index |
---|
64 | ! |
---|
65 | ! 2696 2017-12-14 17:12:51Z kanani |
---|
66 | ! Change in file header (GPL part) |
---|
67 | ! |
---|
68 | ! 2630 2017-11-20 12:58:20Z schwenkel |
---|
69 | ! Removed indices ilog and jlog which are no longer needed since particle box |
---|
70 | ! locations are identical to scalar boxes and topography. |
---|
71 | ! |
---|
72 | ! 2628 2017-11-20 12:40:38Z raasch |
---|
73 | ! bugfix in logarithmic interpolation of v-component (usws was used by mistake) |
---|
74 | ! |
---|
75 | ! 2606 2017-11-10 10:36:31Z schwenkel |
---|
76 | ! Changed particle box locations: center of particle box now coincides |
---|
77 | ! with scalar grid point of same index. |
---|
78 | ! Renamed module and subroutines: lpm_pack_arrays_mod -> lpm_pack_and_sort_mod |
---|
79 | ! lpm_pack_all_arrays -> lpm_sort_in_subboxes, lpm_pack_arrays -> lpm_pack |
---|
80 | ! lpm_sort -> lpm_sort_timeloop_done |
---|
81 | ! |
---|
82 | ! 2417 2017-09-06 15:22:27Z suehring |
---|
83 | ! Particle loops adapted for sub-box structure, i.e. for each sub-box the |
---|
84 | ! particle loop runs from start_index up to end_index instead from 1 to |
---|
85 | ! number_of_particles. This way, it is possible to skip unnecessary |
---|
86 | ! computations for particles that already completed the LES timestep. |
---|
87 | ! |
---|
88 | ! 2318 2017-07-20 17:27:44Z suehring |
---|
89 | ! Get topography top index via Function call |
---|
90 | ! |
---|
91 | ! 2317 2017-07-20 17:27:19Z suehring |
---|
92 | ! |
---|
93 | ! 2232 2017-05-30 17:47:52Z suehring |
---|
94 | ! Adjustments to new topography and surface concept |
---|
95 | ! |
---|
96 | ! 2100 2017-01-05 16:40:16Z suehring |
---|
97 | ! Prevent extremely large SGS-velocities in regions where TKE is zero, e.g. |
---|
98 | ! at the begin of simulations and/or in non-turbulent regions. |
---|
99 | ! |
---|
100 | ! 2000 2016-08-20 18:09:15Z knoop |
---|
101 | ! Forced header and separation lines into 80 columns |
---|
102 | ! |
---|
103 | ! 1936 2016-06-13 13:37:44Z suehring |
---|
104 | ! Formatting adjustments |
---|
105 | ! |
---|
106 | ! 1929 2016-06-09 16:25:25Z suehring |
---|
107 | ! Put stochastic equation in an extra subroutine. |
---|
108 | ! Set flag for stochastic equation to communicate whether a particle is near |
---|
109 | ! topography. This case, memory and drift term are disabled in the Weil equation. |
---|
110 | ! |
---|
111 | ! Enable vertical logarithmic interpolation also above topography. This case, |
---|
112 | ! set a lower limit for the friction velocity, as it can become very small |
---|
113 | ! in narrow street canyons, leading to too large particle speeds. |
---|
114 | ! |
---|
115 | ! 1888 2016-04-21 12:20:49Z suehring |
---|
116 | ! Bugfix concerning logarithmic interpolation of particle speed |
---|
117 | ! |
---|
118 | ! 1822 2016-04-07 07:49:42Z hoffmann |
---|
119 | ! Random velocity fluctuations for particles added. Terminal fall velocity |
---|
120 | ! for droplets is calculated from a parameterization (which is better than |
---|
121 | ! the previous, physically correct calculation, which demands a very short |
---|
122 | ! time step that is not used in the model). |
---|
123 | ! |
---|
124 | ! Unused variables deleted. |
---|
125 | ! |
---|
126 | ! 1691 2015-10-26 16:17:44Z maronga |
---|
127 | ! Renamed prandtl_layer to constant_flux_layer. |
---|
128 | ! |
---|
129 | ! 1685 2015-10-08 07:32:13Z raasch |
---|
130 | ! TKE check for negative values (so far, only zero value was checked) |
---|
131 | ! offset_ocean_nzt_m1 removed |
---|
132 | ! |
---|
133 | ! 1682 2015-10-07 23:56:08Z knoop |
---|
134 | ! Code annotations made doxygen readable |
---|
135 | ! |
---|
136 | ! 1583 2015-04-15 12:16:27Z suehring |
---|
137 | ! Bugfix: particle advection within Prandtl-layer in case of Galilei |
---|
138 | ! transformation. |
---|
139 | ! |
---|
140 | ! 1369 2014-04-24 05:57:38Z raasch |
---|
141 | ! usage of module interfaces removed |
---|
142 | ! |
---|
143 | ! 1359 2014-04-11 17:15:14Z hoffmann |
---|
144 | ! New particle structure integrated. |
---|
145 | ! Kind definition added to all floating point numbers. |
---|
146 | ! |
---|
147 | ! 1322 2014-03-20 16:38:49Z raasch |
---|
148 | ! REAL constants defined as wp_kind |
---|
149 | ! |
---|
150 | ! 1320 2014-03-20 08:40:49Z raasch |
---|
151 | ! ONLY-attribute added to USE-statements, |
---|
152 | ! kind-parameters added to all INTEGER and REAL declaration statements, |
---|
153 | ! kinds are defined in new module kinds, |
---|
154 | ! revision history before 2012 removed, |
---|
155 | ! comment fields (!:) to be used for variable explanations added to |
---|
156 | ! all variable declaration statements |
---|
157 | ! |
---|
158 | ! 1314 2014-03-14 18:25:17Z suehring |
---|
159 | ! Vertical logarithmic interpolation of horizontal particle speed for particles |
---|
160 | ! between roughness height and first vertical grid level. |
---|
161 | ! |
---|
162 | ! 1036 2012-10-22 13:43:42Z raasch |
---|
163 | ! code put under GPL (PALM 3.9) |
---|
164 | ! |
---|
165 | ! 849 2012-03-15 10:35:09Z raasch |
---|
166 | ! initial revision (former part of advec_particles) |
---|
167 | ! |
---|
168 | ! |
---|
169 | ! Description: |
---|
170 | ! ------------ |
---|
171 | !> Calculation of new particle positions due to advection using a simple Euler |
---|
172 | !> scheme. Particles may feel inertia effects. SGS transport can be included |
---|
173 | !> using the stochastic model of Weil et al. (2004, JAS, 61, 2877-2887). |
---|
174 | !------------------------------------------------------------------------------! |
---|
175 | SUBROUTINE lpm_advec (ip,jp,kp) |
---|
176 | |
---|
177 | |
---|
178 | USE arrays_3d, & |
---|
179 | ONLY: de_dx, de_dy, de_dz, diss, dzw, e, km, u, v, w, zu, zw |
---|
180 | |
---|
181 | USE basic_constants_and_equations_mod, & |
---|
182 | ONLY: g, kappa |
---|
183 | |
---|
184 | USE cpulog |
---|
185 | |
---|
186 | USE pegrid |
---|
187 | |
---|
188 | USE control_parameters, & |
---|
189 | ONLY: cloud_droplets, constant_flux_layer, dt_3d, dt_3d_reached_l, & |
---|
190 | dz, topography, u_gtrans, v_gtrans |
---|
191 | |
---|
192 | USE grid_variables, & |
---|
193 | ONLY: dx, dy |
---|
194 | |
---|
195 | USE indices, & |
---|
196 | ONLY: nzb, nzt, wall_flags_0 |
---|
197 | |
---|
198 | USE kinds |
---|
199 | |
---|
200 | USE particle_attributes, & |
---|
201 | ONLY: block_offset, c_0, dt_min_part, grid_particles, iran_part, & |
---|
202 | log_z_z0, number_of_particles, number_of_sublayers, & |
---|
203 | particles, particle_groups, sgs_wf_part, & |
---|
204 | use_sgs_for_particles, vertical_particle_advection, z0_av_global |
---|
205 | |
---|
206 | USE statistics, & |
---|
207 | ONLY: hom |
---|
208 | |
---|
209 | USE surface_mod, & |
---|
210 | ONLY: get_topography_top_index_ji, surf_def_h, surf_lsm_h, surf_usm_h |
---|
211 | |
---|
212 | IMPLICIT NONE |
---|
213 | |
---|
214 | LOGICAL :: subbox_at_wall !< flag to see if the current subgridbox is adjacent to a wall |
---|
215 | |
---|
216 | INTEGER(iwp) :: i !< index variable along x |
---|
217 | INTEGER(iwp) :: ip !< index variable along x |
---|
218 | INTEGER(iwp) :: j !< index variable along y |
---|
219 | INTEGER(iwp) :: jp !< index variable along y |
---|
220 | INTEGER(iwp) :: k !< index variable along z |
---|
221 | INTEGER(iwp) :: k_wall !< vertical index of topography top |
---|
222 | INTEGER(iwp) :: kp !< index variable along z |
---|
223 | INTEGER(iwp) :: kw !< index variable along z |
---|
224 | INTEGER(iwp) :: n !< loop variable over all particles in a grid box |
---|
225 | INTEGER(iwp) :: nb !< block number particles are sorted in |
---|
226 | INTEGER(iwp) :: surf_start !< Index on surface data-type for current grid box |
---|
227 | |
---|
228 | INTEGER(iwp), DIMENSION(0:7) :: start_index !< start particle index for current block |
---|
229 | INTEGER(iwp), DIMENSION(0:7) :: end_index !< start particle index for current block |
---|
230 | |
---|
231 | REAL(wp) :: aa !< dummy argument for horizontal particle interpolation |
---|
232 | REAL(wp) :: bb !< dummy argument for horizontal particle interpolation |
---|
233 | REAL(wp) :: cc !< dummy argument for horizontal particle interpolation |
---|
234 | REAL(wp) :: d_z_p_z0 !< inverse of interpolation length for logarithmic interpolation |
---|
235 | REAL(wp) :: dd !< dummy argument for horizontal particle interpolation |
---|
236 | REAL(wp) :: de_dx_int_l !< x/y-interpolated TKE gradient (x) at particle position at lower vertical level |
---|
237 | REAL(wp) :: de_dx_int_u !< x/y-interpolated TKE gradient (x) at particle position at upper vertical level |
---|
238 | REAL(wp) :: de_dy_int_l !< x/y-interpolated TKE gradient (y) at particle position at lower vertical level |
---|
239 | REAL(wp) :: de_dy_int_u !< x/y-interpolated TKE gradient (y) at particle position at upper vertical level |
---|
240 | REAL(wp) :: de_dt !< temporal derivative of TKE experienced by the particle |
---|
241 | REAL(wp) :: de_dt_min !< lower level for temporal TKE derivative |
---|
242 | REAL(wp) :: de_dz_int_l !< x/y-interpolated TKE gradient (z) at particle position at lower vertical level |
---|
243 | REAL(wp) :: de_dz_int_u !< x/y-interpolated TKE gradient (z) at particle position at upper vertical level |
---|
244 | REAL(wp) :: diameter !< diamter of droplet |
---|
245 | REAL(wp) :: diss_int_l !< x/y-interpolated dissipation at particle position at lower vertical level |
---|
246 | REAL(wp) :: diss_int_u !< x/y-interpolated dissipation at particle position at upper vertical level |
---|
247 | REAL(wp) :: dt_particle_m !< previous particle time step |
---|
248 | REAL(wp) :: dz_temp !< dummy for the vertical grid spacing |
---|
249 | REAL(wp) :: e_int_l !< x/y-interpolated TKE at particle position at lower vertical level |
---|
250 | REAL(wp) :: e_int_u !< x/y-interpolated TKE at particle position at upper vertical level |
---|
251 | REAL(wp) :: e_mean_int !< horizontal mean TKE at particle height |
---|
252 | REAL(wp) :: exp_arg !< argument in the exponent - particle radius |
---|
253 | REAL(wp) :: exp_term !< exponent term |
---|
254 | REAL(wp) :: gg !< dummy argument for horizontal particle interpolation |
---|
255 | REAL(wp) :: height_p !< dummy argument for logarithmic interpolation |
---|
256 | REAL(wp) :: log_z_z0_int !< logarithmus used for surface_layer interpolation |
---|
257 | REAL(wp) :: random_gauss !< Gaussian-distributed random number used for SGS particle advection |
---|
258 | REAL(wp) :: RL !< Lagrangian autocorrelation coefficient |
---|
259 | REAL(wp) :: rg1 !< Gaussian distributed random number |
---|
260 | REAL(wp) :: rg2 !< Gaussian distributed random number |
---|
261 | REAL(wp) :: rg3 !< Gaussian distributed random number |
---|
262 | REAL(wp) :: sigma !< velocity standard deviation |
---|
263 | REAL(wp) :: u_int_l !< x/y-interpolated u-component at particle position at lower vertical level |
---|
264 | REAL(wp) :: u_int_u !< x/y-interpolated u-component at particle position at upper vertical level |
---|
265 | REAL(wp) :: us_int !< friction velocity at particle grid box |
---|
266 | REAL(wp) :: usws_int !< surface momentum flux (u component) at particle grid box |
---|
267 | REAL(wp) :: v_int_l !< x/y-interpolated v-component at particle position at lower vertical level |
---|
268 | REAL(wp) :: v_int_u !< x/y-interpolated v-component at particle position at upper vertical level |
---|
269 | REAL(wp) :: vsws_int !< surface momentum flux (u component) at particle grid box |
---|
270 | REAL(wp) :: vv_int !< dummy to compute interpolated mean SGS TKE, used to scale SGS advection |
---|
271 | REAL(wp) :: w_int_l !< x/y-interpolated w-component at particle position at lower vertical level |
---|
272 | REAL(wp) :: w_int_u !< x/y-interpolated w-component at particle position at upper vertical level |
---|
273 | REAL(wp) :: w_s !< terminal velocity of droplets |
---|
274 | REAL(wp) :: x !< dummy argument for horizontal particle interpolation |
---|
275 | REAL(wp) :: y !< dummy argument for horizontal particle interpolation |
---|
276 | REAL(wp) :: z_p !< surface layer height (0.5 dz) |
---|
277 | |
---|
278 | REAL(wp), PARAMETER :: a_rog = 9.65_wp !< parameter for fall velocity |
---|
279 | REAL(wp), PARAMETER :: b_rog = 10.43_wp !< parameter for fall velocity |
---|
280 | REAL(wp), PARAMETER :: c_rog = 0.6_wp !< parameter for fall velocity |
---|
281 | REAL(wp), PARAMETER :: k_cap_rog = 4.0_wp !< parameter for fall velocity |
---|
282 | REAL(wp), PARAMETER :: k_low_rog = 12.0_wp !< parameter for fall velocity |
---|
283 | REAL(wp), PARAMETER :: d0_rog = 0.745_wp !< separation diameter |
---|
284 | |
---|
285 | REAL(wp), DIMENSION(number_of_particles) :: term_1_2 !< flag to communicate whether a particle is near topography or not |
---|
286 | REAL(wp), DIMENSION(number_of_particles) :: dens_ratio !< ratio between the density of the fluid and the density of the particles |
---|
287 | REAL(wp), DIMENSION(number_of_particles) :: de_dx_int !< horizontal TKE gradient along x at particle position |
---|
288 | REAL(wp), DIMENSION(number_of_particles) :: de_dy_int !< horizontal TKE gradient along y at particle position |
---|
289 | REAL(wp), DIMENSION(number_of_particles) :: de_dz_int !< horizontal TKE gradient along z at particle position |
---|
290 | REAL(wp), DIMENSION(number_of_particles) :: diss_int !< dissipation at particle position |
---|
291 | REAL(wp), DIMENSION(number_of_particles) :: dt_gap !< remaining time until particle time integration reaches LES time |
---|
292 | REAL(wp), DIMENSION(number_of_particles) :: dt_particle !< particle time step |
---|
293 | REAL(wp), DIMENSION(number_of_particles) :: e_int !< TKE at particle position |
---|
294 | REAL(wp), DIMENSION(number_of_particles) :: fs_int !< weighting factor for subgrid-scale particle speed |
---|
295 | REAL(wp), DIMENSION(number_of_particles) :: lagr_timescale !< Lagrangian timescale |
---|
296 | REAL(wp), DIMENSION(number_of_particles) :: rvar1_temp !< SGS particle velocity - u-component |
---|
297 | REAL(wp), DIMENSION(number_of_particles) :: rvar2_temp !< SGS particle velocity - v-component |
---|
298 | REAL(wp), DIMENSION(number_of_particles) :: rvar3_temp !< SGS particle velocity - w-component |
---|
299 | REAL(wp), DIMENSION(number_of_particles) :: u_int !< u-component of particle speed |
---|
300 | REAL(wp), DIMENSION(number_of_particles) :: v_int !< v-component of particle speed |
---|
301 | REAL(wp), DIMENSION(number_of_particles) :: w_int !< w-component of particle speed |
---|
302 | REAL(wp), DIMENSION(number_of_particles) :: xv !< x-position |
---|
303 | REAL(wp), DIMENSION(number_of_particles) :: yv !< y-position |
---|
304 | REAL(wp), DIMENSION(number_of_particles) :: zv !< z-position |
---|
305 | |
---|
306 | REAL(wp), DIMENSION(number_of_particles, 3) :: rg !< vector of Gaussian distributed random numbers |
---|
307 | |
---|
308 | CALL cpu_log( log_point_s(44), 'lpm_advec', 'continue' ) |
---|
309 | |
---|
310 | ! |
---|
311 | !-- Determine height of Prandtl layer and distance between Prandtl-layer |
---|
312 | !-- height and horizontal mean roughness height, which are required for |
---|
313 | !-- vertical logarithmic interpolation of horizontal particle speeds |
---|
314 | !-- (for particles below first vertical grid level). |
---|
315 | z_p = zu(nzb+1) - zw(nzb) |
---|
316 | d_z_p_z0 = 1.0_wp / ( z_p - z0_av_global ) |
---|
317 | |
---|
318 | start_index = grid_particles(kp,jp,ip)%start_index |
---|
319 | end_index = grid_particles(kp,jp,ip)%end_index |
---|
320 | |
---|
321 | xv = particles(1:number_of_particles)%x |
---|
322 | yv = particles(1:number_of_particles)%y |
---|
323 | zv = particles(1:number_of_particles)%z |
---|
324 | |
---|
325 | DO nb = 0, 7 |
---|
326 | ! |
---|
327 | !-- Interpolate u velocity-component |
---|
328 | i = ip |
---|
329 | j = jp + block_offset(nb)%j_off |
---|
330 | k = kp + block_offset(nb)%k_off |
---|
331 | |
---|
332 | DO n = start_index(nb), end_index(nb) |
---|
333 | ! |
---|
334 | !-- Interpolation of the u velocity component onto particle position. |
---|
335 | !-- Particles are interpolation bi-linearly in the horizontal and a |
---|
336 | !-- linearly in the vertical. An exception is made for particles below |
---|
337 | !-- the first vertical grid level in case of a prandtl layer. In this |
---|
338 | !-- case the horizontal particle velocity components are determined using |
---|
339 | !-- Monin-Obukhov relations (if branch). |
---|
340 | !-- First, check if particle is located below first vertical grid level |
---|
341 | !-- above topography (Prandtl-layer height) |
---|
342 | !-- Determine vertical index of topography top |
---|
343 | k_wall = get_topography_top_index_ji( jp, ip, 's' ) |
---|
344 | |
---|
345 | IF ( constant_flux_layer .AND. zv(n) - zw(k_wall) < z_p ) THEN |
---|
346 | ! |
---|
347 | !-- Resolved-scale horizontal particle velocity is zero below z0. |
---|
348 | IF ( zv(n) - zw(k_wall) < z0_av_global ) THEN |
---|
349 | u_int(n) = 0.0_wp |
---|
350 | ELSE |
---|
351 | ! |
---|
352 | !-- Determine the sublayer. Further used as index. |
---|
353 | height_p = ( zv(n) - zw(k_wall) - z0_av_global ) & |
---|
354 | * REAL( number_of_sublayers, KIND=wp ) & |
---|
355 | * d_z_p_z0 |
---|
356 | ! |
---|
357 | !-- Calculate LOG(z/z0) for exact particle height. Therefore, |
---|
358 | !-- interpolate linearly between precalculated logarithm. |
---|
359 | log_z_z0_int = log_z_z0(INT(height_p)) & |
---|
360 | + ( height_p - INT(height_p) ) & |
---|
361 | * ( log_z_z0(INT(height_p)+1) & |
---|
362 | - log_z_z0(INT(height_p)) & |
---|
363 | ) |
---|
364 | ! |
---|
365 | !-- Get friction velocity and momentum flux from new surface data |
---|
366 | !-- types. |
---|
367 | IF ( surf_def_h(0)%start_index(jp,ip) <= & |
---|
368 | surf_def_h(0)%end_index(jp,ip) ) THEN |
---|
369 | surf_start = surf_def_h(0)%start_index(jp,ip) |
---|
370 | !-- Limit friction velocity. In narrow canyons or holes the |
---|
371 | !-- friction velocity can become very small, resulting in a too |
---|
372 | !-- large particle speed. |
---|
373 | us_int = MAX( surf_def_h(0)%us(surf_start), 0.01_wp ) |
---|
374 | usws_int = surf_def_h(0)%usws(surf_start) |
---|
375 | ELSEIF ( surf_lsm_h%start_index(jp,ip) <= & |
---|
376 | surf_lsm_h%end_index(jp,ip) ) THEN |
---|
377 | surf_start = surf_lsm_h%start_index(jp,ip) |
---|
378 | us_int = MAX( surf_lsm_h%us(surf_start), 0.01_wp ) |
---|
379 | usws_int = surf_lsm_h%usws(surf_start) |
---|
380 | ELSEIF ( surf_usm_h%start_index(jp,ip) <= & |
---|
381 | surf_usm_h%end_index(jp,ip) ) THEN |
---|
382 | surf_start = surf_usm_h%start_index(jp,ip) |
---|
383 | us_int = MAX( surf_usm_h%us(surf_start), 0.01_wp ) |
---|
384 | usws_int = surf_usm_h%usws(surf_start) |
---|
385 | ENDIF |
---|
386 | |
---|
387 | ! |
---|
388 | !-- Neutral solution is applied for all situations, e.g. also for |
---|
389 | !-- unstable and stable situations. Even though this is not exact |
---|
390 | !-- this saves a lot of CPU time since several calls of intrinsic |
---|
391 | !-- FORTRAN procedures (LOG, ATAN) are avoided, This is justified |
---|
392 | !-- as sensitivity studies revealed no significant effect of |
---|
393 | !-- using the neutral solution also for un/stable situations. |
---|
394 | u_int(n) = -usws_int / ( us_int * kappa + 1E-10_wp ) & |
---|
395 | * log_z_z0_int - u_gtrans |
---|
396 | |
---|
397 | ENDIF |
---|
398 | ! |
---|
399 | !-- Particle above the first grid level. Bi-linear interpolation in the |
---|
400 | !-- horizontal and linear interpolation in the vertical direction. |
---|
401 | ELSE |
---|
402 | |
---|
403 | x = xv(n) - i * dx |
---|
404 | y = yv(n) + ( 0.5_wp - j ) * dy |
---|
405 | aa = x**2 + y**2 |
---|
406 | bb = ( dx - x )**2 + y**2 |
---|
407 | cc = x**2 + ( dy - y )**2 |
---|
408 | dd = ( dx - x )**2 + ( dy - y )**2 |
---|
409 | gg = aa + bb + cc + dd |
---|
410 | |
---|
411 | u_int_l = ( ( gg - aa ) * u(k,j,i) + ( gg - bb ) * u(k,j,i+1) & |
---|
412 | + ( gg - cc ) * u(k,j+1,i) + ( gg - dd ) * & |
---|
413 | u(k,j+1,i+1) ) / ( 3.0_wp * gg ) - u_gtrans |
---|
414 | |
---|
415 | IF ( k == nzt ) THEN |
---|
416 | u_int(n) = u_int_l |
---|
417 | ELSE |
---|
418 | u_int_u = ( ( gg-aa ) * u(k+1,j,i) + ( gg-bb ) * u(k+1,j,i+1) & |
---|
419 | + ( gg-cc ) * u(k+1,j+1,i) + ( gg-dd ) * & |
---|
420 | u(k+1,j+1,i+1) ) / ( 3.0_wp * gg ) - u_gtrans |
---|
421 | u_int(n) = u_int_l + ( zv(n) - zu(k) ) / dzw(k+1) * & |
---|
422 | ( u_int_u - u_int_l ) |
---|
423 | ENDIF |
---|
424 | |
---|
425 | ENDIF |
---|
426 | |
---|
427 | ENDDO |
---|
428 | ! |
---|
429 | !-- Same procedure for interpolation of the v velocity-component |
---|
430 | i = ip + block_offset(nb)%i_off |
---|
431 | j = jp |
---|
432 | k = kp + block_offset(nb)%k_off |
---|
433 | |
---|
434 | DO n = start_index(nb), end_index(nb) |
---|
435 | |
---|
436 | ! |
---|
437 | !-- Determine vertical index of topography top |
---|
438 | k_wall = get_topography_top_index_ji( jp,ip, 's' ) |
---|
439 | |
---|
440 | IF ( constant_flux_layer .AND. zv(n) - zw(k_wall) < z_p ) THEN |
---|
441 | IF ( zv(n) - zw(k_wall) < z0_av_global ) THEN |
---|
442 | ! |
---|
443 | !-- Resolved-scale horizontal particle velocity is zero below z0. |
---|
444 | v_int(n) = 0.0_wp |
---|
445 | ELSE |
---|
446 | ! |
---|
447 | !-- Determine the sublayer. Further used as index. Please note, |
---|
448 | !-- logarithmus can not be reused from above, as in in case of |
---|
449 | !-- topography particle on u-grid can be above surface-layer height, |
---|
450 | !-- whereas it can be below on v-grid. |
---|
451 | height_p = ( zv(n) - zw(k_wall) - z0_av_global ) & |
---|
452 | * REAL( number_of_sublayers, KIND=wp ) & |
---|
453 | * d_z_p_z0 |
---|
454 | ! |
---|
455 | !-- Calculate LOG(z/z0) for exact particle height. Therefore, |
---|
456 | !-- interpolate linearly between precalculated logarithm. |
---|
457 | log_z_z0_int = log_z_z0(INT(height_p)) & |
---|
458 | + ( height_p - INT(height_p) ) & |
---|
459 | * ( log_z_z0(INT(height_p)+1) & |
---|
460 | - log_z_z0(INT(height_p)) & |
---|
461 | ) |
---|
462 | ! |
---|
463 | !-- Get friction velocity and momentum flux from new surface data |
---|
464 | !-- types. |
---|
465 | IF ( surf_def_h(0)%start_index(jp,ip) <= & |
---|
466 | surf_def_h(0)%end_index(jp,ip) ) THEN |
---|
467 | surf_start = surf_def_h(0)%start_index(jp,ip) |
---|
468 | !-- Limit friction velocity. In narrow canyons or holes the |
---|
469 | !-- friction velocity can become very small, resulting in a too |
---|
470 | !-- large particle speed. |
---|
471 | us_int = MAX( surf_def_h(0)%us(surf_start), 0.01_wp ) |
---|
472 | vsws_int = surf_def_h(0)%vsws(surf_start) |
---|
473 | ELSEIF ( surf_lsm_h%start_index(jp,ip) <= & |
---|
474 | surf_lsm_h%end_index(jp,ip) ) THEN |
---|
475 | surf_start = surf_lsm_h%start_index(jp,ip) |
---|
476 | us_int = MAX( surf_lsm_h%us(surf_start), 0.01_wp ) |
---|
477 | vsws_int = surf_lsm_h%vsws(surf_start) |
---|
478 | ELSEIF ( surf_usm_h%start_index(jp,ip) <= & |
---|
479 | surf_usm_h%end_index(jp,ip) ) THEN |
---|
480 | surf_start = surf_usm_h%start_index(jp,ip) |
---|
481 | us_int = MAX( surf_usm_h%us(surf_start), 0.01_wp ) |
---|
482 | vsws_int = surf_usm_h%vsws(surf_start) |
---|
483 | ENDIF |
---|
484 | ! |
---|
485 | !-- Neutral solution is applied for all situations, e.g. also for |
---|
486 | !-- unstable and stable situations. Even though this is not exact |
---|
487 | !-- this saves a lot of CPU time since several calls of intrinsic |
---|
488 | !-- FORTRAN procedures (LOG, ATAN) are avoided, This is justified |
---|
489 | !-- as sensitivity studies revealed no significant effect of |
---|
490 | !-- using the neutral solution also for un/stable situations. |
---|
491 | v_int(n) = -vsws_int / ( us_int * kappa + 1E-10_wp ) & |
---|
492 | * log_z_z0_int - v_gtrans |
---|
493 | |
---|
494 | ENDIF |
---|
495 | |
---|
496 | ELSE |
---|
497 | x = xv(n) + ( 0.5_wp - i ) * dx |
---|
498 | y = yv(n) - j * dy |
---|
499 | aa = x**2 + y**2 |
---|
500 | bb = ( dx - x )**2 + y**2 |
---|
501 | cc = x**2 + ( dy - y )**2 |
---|
502 | dd = ( dx - x )**2 + ( dy - y )**2 |
---|
503 | gg = aa + bb + cc + dd |
---|
504 | |
---|
505 | v_int_l = ( ( gg - aa ) * v(k,j,i) + ( gg - bb ) * v(k,j,i+1) & |
---|
506 | + ( gg - cc ) * v(k,j+1,i) + ( gg - dd ) * v(k,j+1,i+1) & |
---|
507 | ) / ( 3.0_wp * gg ) - v_gtrans |
---|
508 | |
---|
509 | IF ( k == nzt ) THEN |
---|
510 | v_int(n) = v_int_l |
---|
511 | ELSE |
---|
512 | v_int_u = ( ( gg-aa ) * v(k+1,j,i) + ( gg-bb ) * v(k+1,j,i+1) & |
---|
513 | + ( gg-cc ) * v(k+1,j+1,i) + ( gg-dd ) * v(k+1,j+1,i+1) & |
---|
514 | ) / ( 3.0_wp * gg ) - v_gtrans |
---|
515 | v_int(n) = v_int_l + ( zv(n) - zu(k) ) / dzw(k+1) * & |
---|
516 | ( v_int_u - v_int_l ) |
---|
517 | ENDIF |
---|
518 | |
---|
519 | ENDIF |
---|
520 | |
---|
521 | ENDDO |
---|
522 | ! |
---|
523 | !-- Same procedure for interpolation of the w velocity-component |
---|
524 | i = ip + block_offset(nb)%i_off |
---|
525 | j = jp + block_offset(nb)%j_off |
---|
526 | k = kp - 1 |
---|
527 | |
---|
528 | DO n = start_index(nb), end_index(nb) |
---|
529 | |
---|
530 | IF ( vertical_particle_advection(particles(n)%group) ) THEN |
---|
531 | |
---|
532 | x = xv(n) + ( 0.5_wp - i ) * dx |
---|
533 | y = yv(n) + ( 0.5_wp - j ) * dy |
---|
534 | aa = x**2 + y**2 |
---|
535 | bb = ( dx - x )**2 + y**2 |
---|
536 | cc = x**2 + ( dy - y )**2 |
---|
537 | dd = ( dx - x )**2 + ( dy - y )**2 |
---|
538 | gg = aa + bb + cc + dd |
---|
539 | |
---|
540 | w_int_l = ( ( gg - aa ) * w(k,j,i) + ( gg - bb ) * w(k,j,i+1) & |
---|
541 | + ( gg - cc ) * w(k,j+1,i) + ( gg - dd ) * w(k,j+1,i+1) & |
---|
542 | ) / ( 3.0_wp * gg ) |
---|
543 | |
---|
544 | IF ( k == nzt ) THEN |
---|
545 | w_int(n) = w_int_l |
---|
546 | ELSE |
---|
547 | w_int_u = ( ( gg-aa ) * w(k+1,j,i) + & |
---|
548 | ( gg-bb ) * w(k+1,j,i+1) + & |
---|
549 | ( gg-cc ) * w(k+1,j+1,i) + & |
---|
550 | ( gg-dd ) * w(k+1,j+1,i+1) & |
---|
551 | ) / ( 3.0_wp * gg ) |
---|
552 | w_int(n) = w_int_l + ( zv(n) - zw(k) ) / dzw(k+1) * & |
---|
553 | ( w_int_u - w_int_l ) |
---|
554 | ENDIF |
---|
555 | |
---|
556 | ELSE |
---|
557 | |
---|
558 | w_int(n) = 0.0_wp |
---|
559 | |
---|
560 | ENDIF |
---|
561 | |
---|
562 | ENDDO |
---|
563 | |
---|
564 | ENDDO |
---|
565 | |
---|
566 | !-- Interpolate and calculate quantities needed for calculating the SGS |
---|
567 | !-- velocities |
---|
568 | IF ( use_sgs_for_particles .AND. .NOT. cloud_droplets ) THEN |
---|
569 | |
---|
570 | DO nb = 0,7 |
---|
571 | |
---|
572 | subbox_at_wall = .FALSE. |
---|
573 | ! |
---|
574 | !-- In case of topography check if subbox is adjacent to a wall |
---|
575 | IF ( .NOT. topography == 'flat' ) THEN |
---|
576 | i = ip + MERGE( -1_iwp , 1_iwp, BTEST( nb, 2 ) ) |
---|
577 | j = jp + MERGE( -1_iwp , 1_iwp, BTEST( nb, 1 ) ) |
---|
578 | k = kp + MERGE( -1_iwp , 1_iwp, BTEST( nb, 0 ) ) |
---|
579 | IF ( .NOT. BTEST(wall_flags_0(k, jp, ip), 0) .OR. & |
---|
580 | .NOT. BTEST(wall_flags_0(kp, j, ip), 0) .OR. & |
---|
581 | .NOT. BTEST(wall_flags_0(kp, jp, i ), 0) ) & |
---|
582 | THEN |
---|
583 | subbox_at_wall = .TRUE. |
---|
584 | ENDIF |
---|
585 | ENDIF |
---|
586 | IF ( subbox_at_wall ) THEN |
---|
587 | e_int(start_index(nb):end_index(nb)) = e(kp,jp,ip) |
---|
588 | diss_int(start_index(nb):end_index(nb)) = diss(kp,jp,ip) |
---|
589 | de_dx_int(start_index(nb):end_index(nb)) = de_dx(kp,jp,ip) |
---|
590 | de_dy_int(start_index(nb):end_index(nb)) = de_dy(kp,jp,ip) |
---|
591 | de_dz_int(start_index(nb):end_index(nb)) = de_dz(kp,jp,ip) |
---|
592 | ! |
---|
593 | !-- Set flag for stochastic equation. |
---|
594 | term_1_2(start_index(nb):end_index(nb)) = 0.0_wp |
---|
595 | ELSE |
---|
596 | i = ip + block_offset(nb)%i_off |
---|
597 | j = jp + block_offset(nb)%j_off |
---|
598 | k = kp + block_offset(nb)%k_off |
---|
599 | |
---|
600 | DO n = start_index(nb), end_index(nb) |
---|
601 | ! |
---|
602 | !-- Interpolate TKE |
---|
603 | x = xv(n) + ( 0.5_wp - i ) * dx |
---|
604 | y = yv(n) + ( 0.5_wp - j ) * dy |
---|
605 | aa = x**2 + y**2 |
---|
606 | bb = ( dx - x )**2 + y**2 |
---|
607 | cc = x**2 + ( dy - y )**2 |
---|
608 | dd = ( dx - x )**2 + ( dy - y )**2 |
---|
609 | gg = aa + bb + cc + dd |
---|
610 | |
---|
611 | e_int_l = ( ( gg-aa ) * e(k,j,i) + ( gg-bb ) * e(k,j,i+1) & |
---|
612 | + ( gg-cc ) * e(k,j+1,i) + ( gg-dd ) * e(k,j+1,i+1) & |
---|
613 | ) / ( 3.0_wp * gg ) |
---|
614 | |
---|
615 | IF ( k+1 == nzt+1 ) THEN |
---|
616 | e_int(n) = e_int_l |
---|
617 | ELSE |
---|
618 | e_int_u = ( ( gg - aa ) * e(k+1,j,i) + & |
---|
619 | ( gg - bb ) * e(k+1,j,i+1) + & |
---|
620 | ( gg - cc ) * e(k+1,j+1,i) + & |
---|
621 | ( gg - dd ) * e(k+1,j+1,i+1) & |
---|
622 | ) / ( 3.0_wp * gg ) |
---|
623 | e_int(n) = e_int_l + ( zv(n) - zu(k) ) / dzw(k+1) * & |
---|
624 | ( e_int_u - e_int_l ) |
---|
625 | ENDIF |
---|
626 | ! |
---|
627 | !-- Needed to avoid NaN particle velocities (this might not be |
---|
628 | !-- required any more) |
---|
629 | IF ( e_int(n) <= 0.0_wp ) THEN |
---|
630 | e_int(n) = 1.0E-20_wp |
---|
631 | ENDIF |
---|
632 | ! |
---|
633 | !-- Interpolate the TKE gradient along x (adopt incides i,j,k and |
---|
634 | !-- all position variables from above (TKE)) |
---|
635 | de_dx_int_l = ( ( gg - aa ) * de_dx(k,j,i) + & |
---|
636 | ( gg - bb ) * de_dx(k,j,i+1) + & |
---|
637 | ( gg - cc ) * de_dx(k,j+1,i) + & |
---|
638 | ( gg - dd ) * de_dx(k,j+1,i+1) & |
---|
639 | ) / ( 3.0_wp * gg ) |
---|
640 | |
---|
641 | IF ( ( k+1 == nzt+1 ) .OR. ( k == nzb ) ) THEN |
---|
642 | de_dx_int(n) = de_dx_int_l |
---|
643 | ELSE |
---|
644 | de_dx_int_u = ( ( gg - aa ) * de_dx(k+1,j,i) + & |
---|
645 | ( gg - bb ) * de_dx(k+1,j,i+1) + & |
---|
646 | ( gg - cc ) * de_dx(k+1,j+1,i) + & |
---|
647 | ( gg - dd ) * de_dx(k+1,j+1,i+1) & |
---|
648 | ) / ( 3.0_wp * gg ) |
---|
649 | de_dx_int(n) = de_dx_int_l + ( zv(n) - zu(k) ) / dzw(k+1) * & |
---|
650 | ( de_dx_int_u - de_dx_int_l ) |
---|
651 | ENDIF |
---|
652 | ! |
---|
653 | !-- Interpolate the TKE gradient along y |
---|
654 | de_dy_int_l = ( ( gg - aa ) * de_dy(k,j,i) + & |
---|
655 | ( gg - bb ) * de_dy(k,j,i+1) + & |
---|
656 | ( gg - cc ) * de_dy(k,j+1,i) + & |
---|
657 | ( gg - dd ) * de_dy(k,j+1,i+1) & |
---|
658 | ) / ( 3.0_wp * gg ) |
---|
659 | IF ( ( k+1 == nzt+1 ) .OR. ( k == nzb ) ) THEN |
---|
660 | de_dy_int(n) = de_dy_int_l |
---|
661 | ELSE |
---|
662 | de_dy_int_u = ( ( gg - aa ) * de_dy(k+1,j,i) + & |
---|
663 | ( gg - bb ) * de_dy(k+1,j,i+1) + & |
---|
664 | ( gg - cc ) * de_dy(k+1,j+1,i) + & |
---|
665 | ( gg - dd ) * de_dy(k+1,j+1,i+1) & |
---|
666 | ) / ( 3.0_wp * gg ) |
---|
667 | de_dy_int(n) = de_dy_int_l + ( zv(n) - zu(k) ) / dzw(k+1) * & |
---|
668 | ( de_dy_int_u - de_dy_int_l ) |
---|
669 | ENDIF |
---|
670 | |
---|
671 | ! |
---|
672 | !-- Interpolate the TKE gradient along z |
---|
673 | IF ( zv(n) < 0.5_wp * dz(1) ) THEN |
---|
674 | de_dz_int(n) = 0.0_wp |
---|
675 | ELSE |
---|
676 | de_dz_int_l = ( ( gg - aa ) * de_dz(k,j,i) + & |
---|
677 | ( gg - bb ) * de_dz(k,j,i+1) + & |
---|
678 | ( gg - cc ) * de_dz(k,j+1,i) + & |
---|
679 | ( gg - dd ) * de_dz(k,j+1,i+1) & |
---|
680 | ) / ( 3.0_wp * gg ) |
---|
681 | |
---|
682 | IF ( ( k+1 == nzt+1 ) .OR. ( k == nzb ) ) THEN |
---|
683 | de_dz_int(n) = de_dz_int_l |
---|
684 | ELSE |
---|
685 | de_dz_int_u = ( ( gg - aa ) * de_dz(k+1,j,i) + & |
---|
686 | ( gg - bb ) * de_dz(k+1,j,i+1) + & |
---|
687 | ( gg - cc ) * de_dz(k+1,j+1,i) + & |
---|
688 | ( gg - dd ) * de_dz(k+1,j+1,i+1) & |
---|
689 | ) / ( 3.0_wp * gg ) |
---|
690 | de_dz_int(n) = de_dz_int_l + ( zv(n) - zu(k) ) / dzw(k+1) * & |
---|
691 | ( de_dz_int_u - de_dz_int_l ) |
---|
692 | ENDIF |
---|
693 | ENDIF |
---|
694 | |
---|
695 | ! |
---|
696 | !-- Interpolate the dissipation of TKE |
---|
697 | diss_int_l = ( ( gg - aa ) * diss(k,j,i) + & |
---|
698 | ( gg - bb ) * diss(k,j,i+1) + & |
---|
699 | ( gg - cc ) * diss(k,j+1,i) + & |
---|
700 | ( gg - dd ) * diss(k,j+1,i+1) & |
---|
701 | ) / ( 3.0_wp * gg ) |
---|
702 | |
---|
703 | IF ( k == nzt ) THEN |
---|
704 | diss_int(n) = diss_int_l |
---|
705 | ELSE |
---|
706 | diss_int_u = ( ( gg - aa ) * diss(k+1,j,i) + & |
---|
707 | ( gg - bb ) * diss(k+1,j,i+1) + & |
---|
708 | ( gg - cc ) * diss(k+1,j+1,i) + & |
---|
709 | ( gg - dd ) * diss(k+1,j+1,i+1) & |
---|
710 | ) / ( 3.0_wp * gg ) |
---|
711 | diss_int(n) = diss_int_l + ( zv(n) - zu(k) ) / dzw(k+1) * & |
---|
712 | ( diss_int_u - diss_int_l ) |
---|
713 | ENDIF |
---|
714 | |
---|
715 | ! |
---|
716 | !-- Set flag for stochastic equation. |
---|
717 | term_1_2(n) = 1.0_wp |
---|
718 | ENDDO |
---|
719 | ENDIF |
---|
720 | ENDDO |
---|
721 | |
---|
722 | DO nb = 0,7 |
---|
723 | i = ip + block_offset(nb)%i_off |
---|
724 | j = jp + block_offset(nb)%j_off |
---|
725 | k = kp + block_offset(nb)%k_off |
---|
726 | |
---|
727 | DO n = start_index(nb), end_index(nb) |
---|
728 | ! |
---|
729 | !-- Vertical interpolation of the horizontally averaged SGS TKE and |
---|
730 | !-- resolved-scale velocity variances and use the interpolated values |
---|
731 | !-- to calculate the coefficient fs, which is a measure of the ratio |
---|
732 | !-- of the subgrid-scale turbulent kinetic energy to the total amount |
---|
733 | !-- of turbulent kinetic energy. |
---|
734 | IF ( k == 0 ) THEN |
---|
735 | e_mean_int = hom(0,1,8,0) |
---|
736 | ELSE |
---|
737 | e_mean_int = hom(k,1,8,0) + & |
---|
738 | ( hom(k+1,1,8,0) - hom(k,1,8,0) ) / & |
---|
739 | ( zu(k+1) - zu(k) ) * & |
---|
740 | ( zv(n) - zu(k) ) |
---|
741 | ENDIF |
---|
742 | |
---|
743 | kw = kp - 1 |
---|
744 | |
---|
745 | IF ( k == 0 ) THEN |
---|
746 | aa = hom(k+1,1,30,0) * ( zv(n) / & |
---|
747 | ( 0.5_wp * ( zu(k+1) - zu(k) ) ) ) |
---|
748 | bb = hom(k+1,1,31,0) * ( zv(n) / & |
---|
749 | ( 0.5_wp * ( zu(k+1) - zu(k) ) ) ) |
---|
750 | cc = hom(kw+1,1,32,0) * ( zv(n) / & |
---|
751 | ( 1.0_wp * ( zw(kw+1) - zw(kw) ) ) ) |
---|
752 | ELSE |
---|
753 | aa = hom(k,1,30,0) + ( hom(k+1,1,30,0) - hom(k,1,30,0) ) * & |
---|
754 | ( ( zv(n) - zu(k) ) / ( zu(k+1) - zu(k) ) ) |
---|
755 | bb = hom(k,1,31,0) + ( hom(k+1,1,31,0) - hom(k,1,31,0) ) * & |
---|
756 | ( ( zv(n) - zu(k) ) / ( zu(k+1) - zu(k) ) ) |
---|
757 | cc = hom(kw,1,32,0) + ( hom(kw+1,1,32,0)-hom(kw,1,32,0) ) * & |
---|
758 | ( ( zv(n) - zw(kw) ) / ( zw(kw+1)-zw(kw) ) ) |
---|
759 | ENDIF |
---|
760 | |
---|
761 | vv_int = ( 1.0_wp / 3.0_wp ) * ( aa + bb + cc ) |
---|
762 | ! |
---|
763 | !-- Needed to avoid NaN particle velocities. The value of 1.0 is just |
---|
764 | !-- an educated guess for the given case. |
---|
765 | IF ( vv_int + ( 2.0_wp / 3.0_wp ) * e_mean_int == 0.0_wp ) THEN |
---|
766 | fs_int(n) = 1.0_wp |
---|
767 | ELSE |
---|
768 | fs_int(n) = ( 2.0_wp / 3.0_wp ) * e_mean_int / & |
---|
769 | ( vv_int + ( 2.0_wp / 3.0_wp ) * e_mean_int ) |
---|
770 | ENDIF |
---|
771 | |
---|
772 | ENDDO |
---|
773 | ENDDO |
---|
774 | |
---|
775 | DO nb = 0, 7 |
---|
776 | DO n = start_index(nb), end_index(nb) |
---|
777 | rg(n,1) = random_gauss( iran_part, 5.0_wp ) |
---|
778 | rg(n,2) = random_gauss( iran_part, 5.0_wp ) |
---|
779 | rg(n,3) = random_gauss( iran_part, 5.0_wp ) |
---|
780 | ENDDO |
---|
781 | ENDDO |
---|
782 | |
---|
783 | DO nb = 0, 7 |
---|
784 | DO n = start_index(nb), end_index(nb) |
---|
785 | |
---|
786 | ! |
---|
787 | !-- Calculate the Lagrangian timescale according to Weil et al. (2004). |
---|
788 | lagr_timescale(n) = ( 4.0_wp * e_int(n) + 1E-20_wp ) / & |
---|
789 | ( 3.0_wp * fs_int(n) * c_0 * diss_int(n) + 1E-20_wp ) |
---|
790 | |
---|
791 | ! |
---|
792 | !-- Calculate the next particle timestep. dt_gap is the time needed to |
---|
793 | !-- complete the current LES timestep. |
---|
794 | dt_gap(n) = dt_3d - particles(n)%dt_sum |
---|
795 | dt_particle(n) = MIN( dt_3d, 0.025_wp * lagr_timescale(n), dt_gap(n) ) |
---|
796 | particles(n)%aux1 = lagr_timescale(n) |
---|
797 | particles(n)%aux2 = dt_gap(n) |
---|
798 | ! |
---|
799 | !-- The particle timestep should not be too small in order to prevent |
---|
800 | !-- the number of particle timesteps of getting too large |
---|
801 | IF ( dt_particle(n) < dt_min_part .AND. dt_min_part < dt_gap(n) ) THEN |
---|
802 | dt_particle(n) = dt_min_part |
---|
803 | ENDIF |
---|
804 | rvar1_temp(n) = particles(n)%rvar1 |
---|
805 | rvar2_temp(n) = particles(n)%rvar2 |
---|
806 | rvar3_temp(n) = particles(n)%rvar3 |
---|
807 | ! |
---|
808 | !-- Calculate the SGS velocity components |
---|
809 | IF ( particles(n)%age == 0.0_wp ) THEN |
---|
810 | ! |
---|
811 | !-- For new particles the SGS components are derived from the SGS |
---|
812 | !-- TKE. Limit the Gaussian random number to the interval |
---|
813 | !-- [-5.0*sigma, 5.0*sigma] in order to prevent the SGS velocities |
---|
814 | !-- from becoming unrealistically large. |
---|
815 | rvar1_temp(n) = SQRT( 2.0_wp * sgs_wf_part * e_int(n) & |
---|
816 | + 1E-20_wp ) * ( rg(n,1) - 1.0_wp ) |
---|
817 | rvar2_temp(n) = SQRT( 2.0_wp * sgs_wf_part * e_int(n) & |
---|
818 | + 1E-20_wp ) * ( rg(n,2) - 1.0_wp ) |
---|
819 | rvar3_temp(n) = SQRT( 2.0_wp * sgs_wf_part * e_int(n) & |
---|
820 | + 1E-20_wp ) * ( rg(n,3) - 1.0_wp ) |
---|
821 | |
---|
822 | ELSE |
---|
823 | ! |
---|
824 | !-- Restriction of the size of the new timestep: compared to the |
---|
825 | !-- previous timestep the increase must not exceed 200%. First, |
---|
826 | !-- check if age > age_m, in order to prevent that particles get zero |
---|
827 | !-- timestep. |
---|
828 | dt_particle_m = MERGE( dt_particle(n), & |
---|
829 | particles(n)%age - particles(n)%age_m, & |
---|
830 | particles(n)%age - particles(n)%age_m < & |
---|
831 | 1E-8_wp ) |
---|
832 | IF ( dt_particle(n) > 2.0_wp * dt_particle_m ) THEN |
---|
833 | dt_particle(n) = 2.0_wp * dt_particle_m |
---|
834 | ENDIF |
---|
835 | |
---|
836 | !-- For old particles the SGS components are correlated with the |
---|
837 | !-- values from the previous timestep. Random numbers have also to |
---|
838 | !-- be limited (see above). |
---|
839 | !-- As negative values for the subgrid TKE are not allowed, the |
---|
840 | !-- change of the subgrid TKE with time cannot be smaller than |
---|
841 | !-- -e_int(n)/dt_particle. This value is used as a lower boundary |
---|
842 | !-- value for the change of TKE |
---|
843 | de_dt_min = - e_int(n) / dt_particle(n) |
---|
844 | |
---|
845 | de_dt = ( e_int(n) - particles(n)%e_m ) / dt_particle_m |
---|
846 | |
---|
847 | IF ( de_dt < de_dt_min ) THEN |
---|
848 | de_dt = de_dt_min |
---|
849 | ENDIF |
---|
850 | |
---|
851 | CALL weil_stochastic_eq(rvar1_temp(n), fs_int(n), e_int(n),& |
---|
852 | de_dx_int(n), de_dt, diss_int(n), & |
---|
853 | dt_particle(n), rg(n,1), term_1_2(n) ) |
---|
854 | |
---|
855 | CALL weil_stochastic_eq(rvar2_temp(n), fs_int(n), e_int(n),& |
---|
856 | de_dy_int(n), de_dt, diss_int(n), & |
---|
857 | dt_particle(n), rg(n,2), term_1_2(n) ) |
---|
858 | |
---|
859 | CALL weil_stochastic_eq(rvar3_temp(n), fs_int(n), e_int(n),& |
---|
860 | de_dz_int(n), de_dt, diss_int(n), & |
---|
861 | dt_particle(n), rg(n,3), term_1_2(n) ) |
---|
862 | |
---|
863 | ENDIF |
---|
864 | |
---|
865 | ENDDO |
---|
866 | ENDDO |
---|
867 | ! |
---|
868 | !-- Check if the added SGS velocities result in a violation of the CFL- |
---|
869 | !-- criterion. If yes choose a smaller timestep based on the new velocities |
---|
870 | !-- and calculate SGS velocities again |
---|
871 | dz_temp = zw(kp)-zw(kp-1) |
---|
872 | |
---|
873 | DO nb = 0, 7 |
---|
874 | DO n = start_index(nb), end_index(nb) |
---|
875 | IF ( .NOT. particles(n)%age == 0.0_wp .AND. & |
---|
876 | (ABS( u_int(n) + rvar1_temp(n) ) > (dx/dt_particle(n)) .OR. & |
---|
877 | ABS( v_int(n) + rvar2_temp(n) ) > (dy/dt_particle(n)) .OR. & |
---|
878 | ABS( w_int(n) + rvar3_temp(n) ) > (dz_temp/dt_particle(n)))) THEN |
---|
879 | |
---|
880 | dt_particle(n) = 0.9_wp * MIN( & |
---|
881 | ( dx / ABS( u_int(n) + rvar1_temp(n) ) ), & |
---|
882 | ( dy / ABS( v_int(n) + rvar2_temp(n) ) ), & |
---|
883 | ( dz_temp / ABS( w_int(n) + rvar3_temp(n) ) ) ) |
---|
884 | |
---|
885 | ! |
---|
886 | !-- Reset temporary SGS velocites to "current" ones |
---|
887 | rvar1_temp(n) = particles(n)%rvar1 |
---|
888 | rvar2_temp(n) = particles(n)%rvar2 |
---|
889 | rvar3_temp(n) = particles(n)%rvar3 |
---|
890 | |
---|
891 | de_dt_min = - e_int(n) / dt_particle(n) |
---|
892 | |
---|
893 | de_dt = ( e_int(n) - particles(n)%e_m ) / dt_particle_m |
---|
894 | |
---|
895 | IF ( de_dt < de_dt_min ) THEN |
---|
896 | de_dt = de_dt_min |
---|
897 | ENDIF |
---|
898 | |
---|
899 | CALL weil_stochastic_eq(rvar1_temp(n), fs_int(n), e_int(n),& |
---|
900 | de_dx_int(n), de_dt, diss_int(n), & |
---|
901 | dt_particle(n), rg(n,1), term_1_2(n) ) |
---|
902 | |
---|
903 | CALL weil_stochastic_eq(rvar2_temp(n), fs_int(n), e_int(n),& |
---|
904 | de_dy_int(n), de_dt, diss_int(n), & |
---|
905 | dt_particle(n), rg(n,2), term_1_2(n) ) |
---|
906 | |
---|
907 | CALL weil_stochastic_eq(rvar3_temp(n), fs_int(n), e_int(n),& |
---|
908 | de_dz_int(n), de_dt, diss_int(n), & |
---|
909 | dt_particle(n), rg(n,3), term_1_2(n) ) |
---|
910 | ENDIF |
---|
911 | |
---|
912 | ! |
---|
913 | !-- Update particle velocites |
---|
914 | particles(n)%rvar1 = rvar1_temp(n) |
---|
915 | particles(n)%rvar2 = rvar2_temp(n) |
---|
916 | particles(n)%rvar3 = rvar3_temp(n) |
---|
917 | u_int(n) = u_int(n) + particles(n)%rvar1 |
---|
918 | v_int(n) = v_int(n) + particles(n)%rvar2 |
---|
919 | w_int(n) = w_int(n) + particles(n)%rvar3 |
---|
920 | ! |
---|
921 | !-- Store the SGS TKE of the current timelevel which is needed for |
---|
922 | !-- for calculating the SGS particle velocities at the next timestep |
---|
923 | particles(n)%e_m = e_int(n) |
---|
924 | ENDDO |
---|
925 | ENDDO |
---|
926 | |
---|
927 | ELSE |
---|
928 | ! |
---|
929 | !-- If no SGS velocities are used, only the particle timestep has to |
---|
930 | !-- be set |
---|
931 | dt_particle = dt_3d |
---|
932 | |
---|
933 | ENDIF |
---|
934 | |
---|
935 | dens_ratio = particle_groups(particles(1:number_of_particles)%group)%density_ratio |
---|
936 | |
---|
937 | IF ( ANY( dens_ratio == 0.0_wp ) ) THEN |
---|
938 | DO nb = 0, 7 |
---|
939 | DO n = start_index(nb), end_index(nb) |
---|
940 | |
---|
941 | ! |
---|
942 | !-- Particle advection |
---|
943 | IF ( dens_ratio(n) == 0.0_wp ) THEN |
---|
944 | ! |
---|
945 | !-- Pure passive transport (without particle inertia) |
---|
946 | particles(n)%x = xv(n) + u_int(n) * dt_particle(n) |
---|
947 | particles(n)%y = yv(n) + v_int(n) * dt_particle(n) |
---|
948 | particles(n)%z = zv(n) + w_int(n) * dt_particle(n) |
---|
949 | |
---|
950 | particles(n)%speed_x = u_int(n) |
---|
951 | particles(n)%speed_y = v_int(n) |
---|
952 | particles(n)%speed_z = w_int(n) |
---|
953 | |
---|
954 | ELSE |
---|
955 | ! |
---|
956 | !-- Transport of particles with inertia |
---|
957 | particles(n)%x = particles(n)%x + particles(n)%speed_x * & |
---|
958 | dt_particle(n) |
---|
959 | particles(n)%y = particles(n)%y + particles(n)%speed_y * & |
---|
960 | dt_particle(n) |
---|
961 | particles(n)%z = particles(n)%z + particles(n)%speed_z * & |
---|
962 | dt_particle(n) |
---|
963 | |
---|
964 | ! |
---|
965 | !-- Update of the particle velocity |
---|
966 | IF ( cloud_droplets ) THEN |
---|
967 | ! |
---|
968 | !-- Terminal velocity is computed for vertical direction (Rogers et |
---|
969 | !-- al., 1993, J. Appl. Meteorol.) |
---|
970 | diameter = particles(n)%radius * 2000.0_wp !diameter in mm |
---|
971 | IF ( diameter <= d0_rog ) THEN |
---|
972 | w_s = k_cap_rog * diameter * ( 1.0_wp - EXP( -k_low_rog * diameter ) ) |
---|
973 | ELSE |
---|
974 | w_s = a_rog - b_rog * EXP( -c_rog * diameter ) |
---|
975 | ENDIF |
---|
976 | |
---|
977 | ! |
---|
978 | !-- If selected, add random velocities following Soelch and Kaercher |
---|
979 | !-- (2010, Q. J. R. Meteorol. Soc.) |
---|
980 | IF ( use_sgs_for_particles ) THEN |
---|
981 | lagr_timescale(n) = km(kp,jp,ip) / MAX( e(kp,jp,ip), 1.0E-20_wp ) |
---|
982 | RL = EXP( -1.0_wp * dt_3d / MAX( lagr_timescale(n), & |
---|
983 | 1.0E-20_wp ) ) |
---|
984 | sigma = SQRT( e(kp,jp,ip) ) |
---|
985 | |
---|
986 | rg1 = random_gauss( iran_part, 5.0_wp ) - 1.0_wp |
---|
987 | rg2 = random_gauss( iran_part, 5.0_wp ) - 1.0_wp |
---|
988 | rg3 = random_gauss( iran_part, 5.0_wp ) - 1.0_wp |
---|
989 | |
---|
990 | particles(n)%rvar1 = RL * particles(n)%rvar1 + & |
---|
991 | SQRT( 1.0_wp - RL**2 ) * sigma * rg1 |
---|
992 | particles(n)%rvar2 = RL * particles(n)%rvar2 + & |
---|
993 | SQRT( 1.0_wp - RL**2 ) * sigma * rg2 |
---|
994 | particles(n)%rvar3 = RL * particles(n)%rvar3 + & |
---|
995 | SQRT( 1.0_wp - RL**2 ) * sigma * rg3 |
---|
996 | |
---|
997 | particles(n)%speed_x = u_int(n) + particles(n)%rvar1 |
---|
998 | particles(n)%speed_y = v_int(n) + particles(n)%rvar2 |
---|
999 | particles(n)%speed_z = w_int(n) + particles(n)%rvar3 - w_s |
---|
1000 | ELSE |
---|
1001 | particles(n)%speed_x = u_int(n) |
---|
1002 | particles(n)%speed_y = v_int(n) |
---|
1003 | particles(n)%speed_z = w_int(n) - w_s |
---|
1004 | ENDIF |
---|
1005 | |
---|
1006 | ELSE |
---|
1007 | |
---|
1008 | IF ( use_sgs_for_particles ) THEN |
---|
1009 | exp_arg = particle_groups(particles(n)%group)%exp_arg |
---|
1010 | exp_term = EXP( -exp_arg * dt_particle(n) ) |
---|
1011 | ELSE |
---|
1012 | exp_arg = particle_groups(particles(n)%group)%exp_arg |
---|
1013 | exp_term = particle_groups(particles(n)%group)%exp_term |
---|
1014 | ENDIF |
---|
1015 | particles(n)%speed_x = particles(n)%speed_x * exp_term + & |
---|
1016 | u_int(n) * ( 1.0_wp - exp_term ) |
---|
1017 | particles(n)%speed_y = particles(n)%speed_y * exp_term + & |
---|
1018 | v_int(n) * ( 1.0_wp - exp_term ) |
---|
1019 | particles(n)%speed_z = particles(n)%speed_z * exp_term + & |
---|
1020 | ( w_int(n) - ( 1.0_wp - dens_ratio(n) ) * & |
---|
1021 | g / exp_arg ) * ( 1.0_wp - exp_term ) |
---|
1022 | ENDIF |
---|
1023 | |
---|
1024 | ENDIF |
---|
1025 | ENDDO |
---|
1026 | ENDDO |
---|
1027 | |
---|
1028 | ELSE |
---|
1029 | |
---|
1030 | DO nb = 0, 7 |
---|
1031 | DO n = start_index(nb), end_index(nb) |
---|
1032 | ! |
---|
1033 | !-- Transport of particles with inertia |
---|
1034 | particles(n)%x = xv(n) + particles(n)%speed_x * dt_particle(n) |
---|
1035 | particles(n)%y = yv(n) + particles(n)%speed_y * dt_particle(n) |
---|
1036 | particles(n)%z = zv(n) + particles(n)%speed_z * dt_particle(n) |
---|
1037 | ! |
---|
1038 | !-- Update of the particle velocity |
---|
1039 | IF ( cloud_droplets ) THEN |
---|
1040 | ! |
---|
1041 | !-- Terminal velocity is computed for vertical direction (Rogers et al., |
---|
1042 | !-- 1993, J. Appl. Meteorol.) |
---|
1043 | diameter = particles(n)%radius * 2000.0_wp !diameter in mm |
---|
1044 | IF ( diameter <= d0_rog ) THEN |
---|
1045 | w_s = k_cap_rog * diameter * ( 1.0_wp - EXP( -k_low_rog * diameter ) ) |
---|
1046 | ELSE |
---|
1047 | w_s = a_rog - b_rog * EXP( -c_rog * diameter ) |
---|
1048 | ENDIF |
---|
1049 | |
---|
1050 | ! |
---|
1051 | !-- If selected, add random velocities following Soelch and Kaercher |
---|
1052 | !-- (2010, Q. J. R. Meteorol. Soc.) |
---|
1053 | IF ( use_sgs_for_particles ) THEN |
---|
1054 | lagr_timescale(n) = km(kp,jp,ip) / MAX( e(kp,jp,ip), 1.0E-20_wp ) |
---|
1055 | RL = EXP( -1.0_wp * dt_3d / MAX( lagr_timescale(n), & |
---|
1056 | 1.0E-20_wp ) ) |
---|
1057 | sigma = SQRT( e(kp,jp,ip) ) |
---|
1058 | |
---|
1059 | rg1 = random_gauss( iran_part, 5.0_wp ) - 1.0_wp |
---|
1060 | rg2 = random_gauss( iran_part, 5.0_wp ) - 1.0_wp |
---|
1061 | rg3 = random_gauss( iran_part, 5.0_wp ) - 1.0_wp |
---|
1062 | |
---|
1063 | particles(n)%rvar1 = RL * particles(n)%rvar1 + & |
---|
1064 | SQRT( 1.0_wp - RL**2 ) * sigma * rg1 |
---|
1065 | particles(n)%rvar2 = RL * particles(n)%rvar2 + & |
---|
1066 | SQRT( 1.0_wp - RL**2 ) * sigma * rg2 |
---|
1067 | particles(n)%rvar3 = RL * particles(n)%rvar3 + & |
---|
1068 | SQRT( 1.0_wp - RL**2 ) * sigma * rg3 |
---|
1069 | |
---|
1070 | particles(n)%speed_x = u_int(n) + particles(n)%rvar1 |
---|
1071 | particles(n)%speed_y = v_int(n) + particles(n)%rvar2 |
---|
1072 | particles(n)%speed_z = w_int(n) + particles(n)%rvar3 - w_s |
---|
1073 | ELSE |
---|
1074 | particles(n)%speed_x = u_int(n) |
---|
1075 | particles(n)%speed_y = v_int(n) |
---|
1076 | particles(n)%speed_z = w_int(n) - w_s |
---|
1077 | ENDIF |
---|
1078 | |
---|
1079 | ELSE |
---|
1080 | |
---|
1081 | IF ( use_sgs_for_particles ) THEN |
---|
1082 | exp_arg = particle_groups(particles(n)%group)%exp_arg |
---|
1083 | exp_term = EXP( -exp_arg * dt_particle(n) ) |
---|
1084 | ELSE |
---|
1085 | exp_arg = particle_groups(particles(n)%group)%exp_arg |
---|
1086 | exp_term = particle_groups(particles(n)%group)%exp_term |
---|
1087 | ENDIF |
---|
1088 | particles(n)%speed_x = particles(n)%speed_x * exp_term + & |
---|
1089 | u_int(n) * ( 1.0_wp - exp_term ) |
---|
1090 | particles(n)%speed_y = particles(n)%speed_y * exp_term + & |
---|
1091 | v_int(n) * ( 1.0_wp - exp_term ) |
---|
1092 | particles(n)%speed_z = particles(n)%speed_z * exp_term + & |
---|
1093 | ( w_int(n) - ( 1.0_wp - dens_ratio(n) ) * g / & |
---|
1094 | exp_arg ) * ( 1.0_wp - exp_term ) |
---|
1095 | ENDIF |
---|
1096 | ENDDO |
---|
1097 | ENDDO |
---|
1098 | |
---|
1099 | ENDIF |
---|
1100 | |
---|
1101 | ! |
---|
1102 | !-- Store the old age of the particle ( needed to prevent that a |
---|
1103 | !-- particle crosses several PEs during one timestep, and for the |
---|
1104 | !-- evaluation of the subgrid particle velocity fluctuations ) |
---|
1105 | particles(1:number_of_particles)%age_m = particles(1:number_of_particles)%age |
---|
1106 | |
---|
1107 | DO nb = 0, 7 |
---|
1108 | DO n = start_index(nb), end_index(nb) |
---|
1109 | ! |
---|
1110 | !-- Increment the particle age and the total time that the particle |
---|
1111 | !-- has advanced within the particle timestep procedure |
---|
1112 | particles(n)%age = particles(n)%age + dt_particle(n) |
---|
1113 | particles(n)%dt_sum = particles(n)%dt_sum + dt_particle(n) |
---|
1114 | |
---|
1115 | ! |
---|
1116 | !-- Check whether there is still a particle that has not yet completed |
---|
1117 | !-- the total LES timestep |
---|
1118 | IF ( ( dt_3d - particles(n)%dt_sum ) > 1E-8_wp ) THEN |
---|
1119 | dt_3d_reached_l = .FALSE. |
---|
1120 | ENDIF |
---|
1121 | |
---|
1122 | ENDDO |
---|
1123 | ENDDO |
---|
1124 | |
---|
1125 | CALL cpu_log( log_point_s(44), 'lpm_advec', 'pause' ) |
---|
1126 | |
---|
1127 | |
---|
1128 | END SUBROUTINE lpm_advec |
---|
1129 | |
---|
1130 | ! Description: |
---|
1131 | ! ------------ |
---|
1132 | !> Calculation of subgrid-scale particle speed using the stochastic model |
---|
1133 | !> of Weil et al. (2004, JAS, 61, 2877-2887). |
---|
1134 | !------------------------------------------------------------------------------! |
---|
1135 | SUBROUTINE weil_stochastic_eq( v_sgs, fs_n, e_n, dedxi_n, dedt_n, diss_n, & |
---|
1136 | dt_n, rg_n, fac ) |
---|
1137 | |
---|
1138 | USE kinds |
---|
1139 | |
---|
1140 | USE particle_attributes, & |
---|
1141 | ONLY: c_0, sgs_wf_part |
---|
1142 | |
---|
1143 | IMPLICIT NONE |
---|
1144 | |
---|
1145 | REAL(wp) :: a1 !< dummy argument |
---|
1146 | REAL(wp) :: dedt_n !< time derivative of TKE at particle position |
---|
1147 | REAL(wp) :: dedxi_n !< horizontal derivative of TKE at particle position |
---|
1148 | REAL(wp) :: diss_n !< dissipation at particle position |
---|
1149 | REAL(wp) :: dt_n !< particle timestep |
---|
1150 | REAL(wp) :: e_n !< TKE at particle position |
---|
1151 | REAL(wp) :: fac !< flag to identify adjacent topography |
---|
1152 | REAL(wp) :: fs_n !< weighting factor to prevent that subgrid-scale particle speed becomes too large |
---|
1153 | REAL(wp) :: rg_n !< random number |
---|
1154 | REAL(wp) :: term1 !< memory term |
---|
1155 | REAL(wp) :: term2 !< drift correction term |
---|
1156 | REAL(wp) :: term3 !< random term |
---|
1157 | REAL(wp) :: v_sgs !< subgrid-scale velocity component |
---|
1158 | |
---|
1159 | !-- At first, limit TKE to a small non-zero number, in order to prevent |
---|
1160 | !-- the occurrence of extremely large SGS-velocities in case TKE is zero, |
---|
1161 | !-- (could occur at the simulation begin). |
---|
1162 | e_n = MAX( e_n, 1E-20_wp ) |
---|
1163 | ! |
---|
1164 | !-- Please note, terms 1 and 2 (drift and memory term, respectively) are |
---|
1165 | !-- multiplied by a flag to switch of both terms near topography. |
---|
1166 | !-- This is necessary, as both terms may cause a subgrid-scale velocity build up |
---|
1167 | !-- if particles are trapped in regions with very small TKE, e.g. in narrow street |
---|
1168 | !-- canyons resolved by only a few grid points. Hence, term 1 and term 2 are |
---|
1169 | !-- disabled if one of the adjacent grid points belongs to topography. |
---|
1170 | !-- Moreover, in this case, the previous subgrid-scale component is also set |
---|
1171 | !-- to zero. |
---|
1172 | |
---|
1173 | a1 = fs_n * c_0 * diss_n |
---|
1174 | ! |
---|
1175 | !-- Memory term |
---|
1176 | term1 = - a1 * v_sgs * dt_n / ( 4.0_wp * sgs_wf_part * e_n + 1E-20_wp ) & |
---|
1177 | * fac |
---|
1178 | ! |
---|
1179 | !-- Drift correction term |
---|
1180 | term2 = ( ( dedt_n * v_sgs / e_n ) + dedxi_n ) * 0.5_wp * dt_n & |
---|
1181 | * fac |
---|
1182 | ! |
---|
1183 | !-- Random term |
---|
1184 | term3 = SQRT( MAX( a1, 1E-20_wp ) ) * ( rg_n - 1.0_wp ) * SQRT( dt_n ) |
---|
1185 | ! |
---|
1186 | !-- In cese one of the adjacent grid-boxes belongs to topograhy, the previous |
---|
1187 | !-- subgrid-scale velocity component is set to zero, in order to prevent a |
---|
1188 | !-- velocity build-up. |
---|
1189 | !-- This case, set also previous subgrid-scale component to zero. |
---|
1190 | v_sgs = v_sgs * fac + term1 + term2 + term3 |
---|
1191 | |
---|
1192 | END SUBROUTINE weil_stochastic_eq |
---|